In the prior art relating to pneumatic tools, the front end plate for the pneumatic motor is usually provided with a bearing seat, and a bearing is retained in the bearing seat for journaling the rotor shaft. The end of the rotor shaft is normally provided with a pinion gear, and the pinion gear engages suitable gearing in the tool housing. For reasons of compactness, the gearing may comprise planetary gearing carried by an output spindle journaled in the housing. The planetary gearing engages the pinion gear and cooperates with a separate internal ring gear mounted within the housing.